US Navy sonar & divers

[D_B]

This is the part I objected to (in bold) ...
"The U.S. District Court on Jan. 3 required the Navy, among other measures, to maintain a 12 nautical mile no-sonar buffer zone along the California coastline; to shut down sonar when marine mammals were spotted within 2,000 meters; and to monitor for marine mammals using various methods."

Yeah .. like that's the way to conduct training in battle simulated conditions


Edit: Fine to have areas off limits, but to have to shut down from using their sonar when just spotting a wale is not I think, reasonable response ..

 

[Rickg]

Here is a link to the Navy's website on LFA for anyone that might be interested. Probably more information than 99.99% of us are interested in but some of you that aren't already familiar with this sonar system might find it of interest.

SURTASS LFA

LFA is not the type of sonar that the recent court decision was about.

Something to also keep in mind when considering active sonar source levels is that while the # might sound high, those levels decrease by 3db every time the distance from the source doubles (initially measured for 1 meter from the source). An active signal that measures 180db at 1m from the source is 177db at 2m, 174db at 4m, 171db at 8db at 8m, etc so even for powerful sources, a receiver (person, whale, fish, etc) doesn't have to be too far away before the signal is no longer a danger.

Everything I've mentioned here regarding active sonar source levels is available in basic textbooks that discuss the physics of sound in the ocean.

Rickg

 

[Kim]

It seems that Dear Leader Bush has said that the US Navy doesn't need to pay any attention to such things as court orders - pesky things that they are!

 

[rollerboi]

Just thought I'd post a followup that's not in Whine & Cheez (??)...

Nation & World | Navy Must Comply With No-Sonar Rule | Seattle Times Newspaper

A judge has declared Bush's Jan. 15th exemption invalid.

 

[paddyp]

NRDC: Press Release - Bush Attempts Illegal Override of Court Order Protecting Whales from Sonar

"Judge Cooper ruled that the Navy’s scheme to mitigate harm had been “grossly inadequate to protect marine mammals from debilitating levels of sonar exposure” in Southern California’s rich biological waters. Her injunction required the Navy to maintain a 12 nautical mile no-sonar buffer zone along the California coastline; to shut down sonar when marine mammals were spotted within 2,000 meters; and to monitor for marine mammals using various methods, among other measures. "

U.S. President Exempts Navy From Environmental Law
A federal judge in Los Angeles had issued a preliminary injunction earlier this month requiring the Navy to create a 12-nautical-mile (22-kilometer), no-sonar zone along the Southern California coast and to post trained lookouts to watch for marine mammals before and during exercises. Sonar would have to be shut down when mammals are spotted within 2,200 yards (2,000 meters), under the order.


http://www.scubaboard.com/forums/ocean-conservation/316009-seismic-survey-effects-when-diving.html